Apparatus for the production of sound castings



(No Model.)

J. IRWIN, Jr. APPARATUS POP PHP PRODUCTION OP- SOUND OASTPNOS.

N0. 359,974. lateuted Mar. 22, 1887.

sulfur-P 70 @pali-Plein UNITED STATES PATENT EriceQ JOHN IEVIN, JR., OE EDGEVORTH, ASSIGNOR TO THE PITTSBURGH STEEL CASTING COMPANY, OF PITTSBURG, PENNSYLVANIA.

APPARATUS FORTHE PRODUCTION OF SOUND CASTlNGS.

SPECIFICATION forming part of Letters Patent No.359.974, dated March 22, 1887. Application tiled Juy l-l, 1386. ASerial 'No 207.9611. (No model.)

To @ZZ whom, it may concern: above stated, the heat of these masses of metal Be it known that I, JOHN IRWIN, J r., reis no greater than that of the metal poured siding at Edgeworth, in the county of Alleinto the mold, and is liable to cool more rapgheny and State of Pennsylvania, Ia citizen of idly, owing to their exposed condition, as com- 5 the United States, have invented or discovpared with that of the metal in the mold. 55 ered certain new and useful Improvements in The object of the invention is to provide Apparatus for the Production of Sound Castfor the application of a degree of heat at least ings, of which improvement the following is equal to that of the molten metal when poured a specification. at and around the top portion 0f the mold,

1e In the accompanying drawings, which make and for the maintenance of such a degree of 6o part of this specification, Figure l is a view heat for as long a period as necessary, thereby in sectional elevation of my improved heatinsuring a constant supply of molten metal ing apparatus in position over a mold, a porat the upper portion of the mold, wherewith tion of which is also shown in sectional eleto replace that drawn from the center by the 15 vation. Fig. 2 is a horizontal section on the contraction toward the sides. 65 lines a' fr, Fig. l. In making large castings the molds therefor The invention relates to certain improveare usually placed in a pit, with their upper ments in apparatus for the production of iron ends on a level with or very slightly projector steel castings practically free from blowing above the surface of the foundry-floor, as

2o holes and other defects arising from unequal shown at l in Fig. 1. 7o cooling and contraction of the metal in the In carrying out my invention the mold l is mold. prepared in the usual manner, with a sinker- Great difficulty has been heretofore encoun head of sufficient capacity to replace any loss tered in producinglargeingots and other castin the central portion of the mold caused by 25 ings free from blow-holes and other internal the contraction or shrinking of the metal in 75 cavities and porosity caused by the shrinking cooling. As soon as the mold and sinkeror contraction of the metal during cooling. head have been filled with metal a furnace, 2, These defects arise from the fact that the metal capable of generating sufficient heat to retain in the mold cools more rapidly around the metal in the mold in a molten condition, is 3o sides and at the top of the mold than elseplaced over the mold and kept there until the 8o where, as such parts are more exposed, and metal in the mold proper has cooled and sohence the heat thereof radiates away with conliditied. The heat generated by this furnace siderable rapidity. As the metal chills and will heat not only the top of the mold directly solidifies at the sides an external rigid shell is subjected thereto, but the heat will penetrate 3,5 formed, toward which the molten or semifor a considerable distance down along the 85 molten metal in the interior of the casting is mold, thereby retarding the chilling and condrawn, thus forming internal cavities or prosequent solidificaticn of the metal. Under ducing a considerable amount of porosity. It these conditions the cooling and soliditication has been attempted in many ways to keep the of the metal will occur from the bottom of 40 metal at the top of the mold in a molten conthe casting upward, and the superincumbent 90 dition, in order that it may flow down and ll metal will be in such a state of fluidity that the cavities formed, as above stated, during it will flow down and fill the cavities formed the chilling of the sides of the casting. The by the shrinkage of the metal below. In means heretofore resorted to have been only addition to the advantages above stated the 4 5 partially successful, owing to the fact that no maintenance of the metal in a fluid condition 95 greater heat than that ofthe metal poured affords an opportunity for the escape of gas into the mold has been used for this purpose. from the metal, thus avoiding the formation As, :for example, large sinker-heads or auxof blow-holes. iliary bodies of metal have been arranged at Although any furnace in which the desired 5o or around the top of the main mold; but, as degree of heat can be generated and maintained roo is suitable and can be applied for the purpose above specified, I prefer to use a furnace con structed as hereinafter described.

The furnace l2, shown in the drawings, con-i sists of a shell-casing, 3, lined with fire-brick, and preferably mounted ou wheels or rollers 4, for convenience of movement, although it may be moved by means of a crane or other suitable device. VVithinthe casing 3 is formed a combustion or heating chamber, 5,preferabl y annular in contour, the Walls of which are formed of fire clay or brick, and are supportedl by a metal plate, 6, forming the `bottom of the furnace, said plate having an opening corresponding in area to the mouth of the chamber A5. Between the casing and the Walls of the combustion-chamber a checkeuwork of firebrick is formed, the space occupied by the checker-work being divided into two com partments or regenerative chambers, 7 and S, by` lWall 9, extending over the chamber 5 and dia- `pose` above speciiied gas is admitted, as, .for

example, through the tine 16, and is burned in the chamber 5, air being supplied thereto through the inlet-pipe 10, the regenerative chamber 7, and the Hue 16. v The damper on -the stack l2 being closed and that on the stack 13 being opened, the products of combustion escape through the flue 17, the regenerative chamber S, and stack 13. v As soon as `the checker-Work in the chamber 8 has been thoroughly heated by the products of combustion passing therethrough theldampers 14 andil are reversed, and gas is admitted` through the iue17, air being admitted through the pipe 11and chamber 8, Where itis highly heated before mixing with the gas in the flue 17. The products of combustion escape through `the chamber 7 and stack l 12 highlyheating `the checker-Work in said chamber.

As soon as the furnace is in good Working i order it is moved over `the mold 1, into which the metal has been cast, and the space between the bottom of the furnace and the top: ofthe moldon the floor adjacent thereto being closed by sand or in any suitable lmanner `the furl nace is operated in the manner above stated. Vith such a furnace it is possible to obtain a heat much above the melting-point` of ironor steel, and hence the metal iu the `upper porl tion `ofthe mold can be maintained in a molten condition as long as desired. Then desired, the heat in furnace can be gradually reduced, so as to permit of the complete cooling of the top ofthe casting.

I claim 'herein as my invention 1. The combinationof a moldand a portable heat-generatin g apparatus constructed to cover and surround the mouth lof the mold, substantially as set forth.

2; The combination of a mold and a portable regenerative furnace constructedto cover and surround the mouth ofthe mold, substantially as set forth.

In testimony whereof l have hereunto set my hand.

JOHN IRWIN, JR. t

Vi tnesses:

NV. B. CORWIN, DARWIN S. WoLoorT. 

